Black Grouse
In Britain Black Grouse can be found in a number of forest and moorland areas from Scotland down to mid Wales.  They used to be common quite in quite a few of our national parks including the Peak district. There are still some strongholds such as Upper Teesdale and Speyside, but are becoming increasingly rare, this is due to loss of habitat and disturbance at the breeding ground.  In Europe they have a smaller range than Capercaillie but can be found in some sizable flocks in some areas particularly Scandinavia.  In Britain, at the lek, Black Grouse are schedule one, protected birds which can be photographed with appropriate authority.  I have seen and photographed Black Grouse in Britain, Norway, and Finland.  One of the classic wildlife sights is Black Grouse at their Lekking grounds in fresh snow, which I was fortunate to photograph in Finland.
Willow Grouse
Willow Grouse are not a "British bird" but never the less, I was very pleased to see this male whilst in Finland in March 2012.  It was an unexpected but welcome bonus to photograph him while we were searching for Owls, Woodpeckers, and Eagles, and other Northern winter birds to photograph.